A multi-center, randomized trial conducted in China has demonstrated that linear ablation combined with ethanol infusion via the vein of Marshall (EIVOM) in addition to pulmonary vein isolation (PVI) significantly improves outcomes for patients with persistent atrial fibrillation (AF). The PROMPT-AF trial, involving 498 patients across 12 hospitals, found a notable increase in freedom from atrial arrhythmia recurrence without antiarrhythmic drugs compared to PVI alone. This study, published in JAMA Network, highlights a potential advancement in the treatment of persistent AF, a condition known for its challenges in achieving long-term rhythm control.
Study Design and Methods
The PROMPT-AF trial enrolled patients aged 18 to 80 years with AF persisting for more than three months, who were undergoing first-time AF ablation. Participants were randomized to either PVI alone or PVI plus EIVOM and linear ablation of the left atrial roof, mitral isthmus, and cavotricuspid isthmus. The primary endpoint was freedom from documented atrial arrhythmias lasting more than 30 seconds, without antiarrhythmic drugs, within 12 months post-ablation. Secondary outcomes included freedom from atrial arrhythmia recurrence, AF burden, and quality of life improvements. Rhythm monitoring was conducted using wearable single-lead electrocardiographic (ECG) patches, supplemented by symptom-triggered ECGs and Holter monitoring.
Key Findings
After a 12-month follow-up, 70.7% of patients in the PVI plus EIVOM and linear ablation group remained free from atrial arrhythmias without antiarrhythmic drugs, compared to 61.5% in the PVI alone group (hazard ratio, 0.73; 95% CI, 0.54-0.99, P = .045). The intervention effect was consistent across all pre-specified subgroups. While secondary outcomes did not demonstrate significant differences, the study suggests a clinically meaningful improvement in rhythm control with the combined approach.
Clinical Implications
Pulmonary vein isolation (PVI) has been the cornerstone of catheter ablation for atrial fibrillation (AF), but its effectiveness is limited in persistent AF cases. Additional linear ablation beyond PVI has been explored, but its superiority over PVI alone has not been consistently proven. Ethanol infusion of the vein of Marshall (EIVOM) facilitates ablation at the mitral isthmus and may lead to improved effectiveness of a linear ablation strategy. The PROMPT-AF trial demonstrates that linear ablation combined with EIVOM offers a significant advantage in maintaining sinus rhythm in patients with persistent AF.
Procedural Details and Safety
The combination of linear ablation plus EIVOM was associated with a longer mean procedure time (188.0 vs 140.8 minutes, P < .001) and fluoroscopy time (15.9 vs 5.1 minutes, P < .001). Bilateral PVI was successfully achieved in nearly all patients. In the intervention group, EIVOM was successful in 85% of patients, and complete linear block was achieved in a high percentage of patients for the cavotricuspid isthmus (94.3%), roofline (87.4%), and mitral isthmus (87.4%). There was no significant difference in the overall incidence of procedural-related adverse events between groups, although pericarditis or pericardial effusion occurred more frequently in the intervention group (7 patients vs. 0 in the PVI alone group).
Expert Commentary
"The PROMPT-AF trial is the first randomized study to demonstrate that a linear ablation strategy including EIVOM in addition to PVI significantly reduced atrial arrhythmia recurrence compared with PVI alone," the researchers noted. They also acknowledged that while the combined approach improves success rates, it comes with increased procedural time and fluoroscopy exposure. Further refinement of the ablation strategy may enhance atrial compartmentalization and prevent arrhythmia recurrence.
Limitations
The study's limitations include the lack of implantable loop recorders for continuous monitoring, which may underestimate atrial arrhythmia recurrence. Additionally, the trial exclusively included patients with persistent AF lasting longer than 3 months, limiting the generalizability to those with shorter episodes of persistent AF.
